[ARM] VFP: fix section mismatch error

Fix a real section mismatch issue; the test code is thrown away after
initialisation, but if we do not detect the VFP hardware, it is left
hooked into the exception handler.  Any VFP instructions which are
subsequently executed risk calling the discarded exception handler.

Introduce a new "null" handler which returns to the "unrecognised
fault" return address.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/vfp/entry.S

@@ -29,6 +29,10 @@ do_vfp:
 	add	r10, r10, #TI_VFPSTATE	@ r10 = workspace
 	ldr	pc, [r4]		@ call VFP entry point
 
+ENTRY(vfp_null_entry)
+	mov	pc, lr
+ENDPROC(vfp_null_entry)
+
 .LCvfp:
 	.word	vfp_vector
 

arch/arm/vfp/vfpmodule.c

@@ -26,8 +26,9 @@
  */
 void vfp_testing_entry(void);
 void vfp_support_entry(void);
+void vfp_null_entry(void);
 
-void (*vfp_vector)(void) = vfp_testing_entry;
+void (*vfp_vector)(void) = vfp_null_entry;
 union vfp_state *last_VFP_context[NR_CPUS];
 
 /*
@@ -321,8 +322,10 @@ static int __init vfp_init(void)
 	 * The handler is already setup to just log calls, so
 	 * we just need to read the VFPSID register.
 	 */
+	vfp_vector = vfp_testing_entry;
 	vfpsid = fmrx(FPSID);
 	barrier();
+	vfp_vector = vfp_null_entry;
 
 	printk(KERN_INFO "VFP support v0.3: ");
 	if (VFP_arch) {

include/asm-arm/linkage.h

@@ -4,4 +4,8 @@
 #define __ALIGN .align 0
 #define __ALIGN_STR ".align 0"
 
+#define ENDPROC(name) \
+  .type name, %function; \
+  END(name)
+
 #endif